Tell about Domain-Driven Design (DDD) in your project.

Domain-Driven Design (DDD) is an approach to software development focused on a deep understanding of the subject area and modeling it in code.

In my project for developing a hotel booking system, I applied DDD as follows:

• Domain Model: identified main entities — Booking, Room, Customer.
• Aggregates: Booking was an aggregate managing the state of the reservation and related entities.
• Repositories: implemented interfaces for data access, hiding storage details.
• Domain Services: business logic, such as checking room availability, was implemented in domain services.

This allowed for a clear separation of responsibilities, easier maintenance and extension of the system, and made the code more understandable for domain experts.